O EFFECT OF DIET ON THE ALBINO RAT 



Changes in the amount of the running activity are correct indicators 

 of similar fluctuations in the other activities of the animal. 



FEEDING. 



No attempt was made to give a definite amount of protein food in 

 the diet nor to try to maintain nitrogenous equilibrium. The diet was 

 varied as much as possible, and the amount of food given was more 

 than was eaten before the feeding time on the following day. The 

 feed and water boxes were then cleaned and a new supply given. 

 Cracked corn was always given. The young were weaned at the age of 

 28 days and placed in their respective cages, as already described. A 

 rich mixed diet, consisting largely of bread and milk with an occasional 

 feed of baked beans and meat hash, was given all to prevent any dis- 

 astrous effects resulting from the sudden change in environment and 

 methods of feeding. This mixed diet was continued for twenty-eight 

 days. At this age (fifty-six days) all appeared perfectly healthy and 

 normal in every respect. They had each made a normal gain. The 

 males averaged 70.1 grams and the females 59.3 grams. 



The difference in the character of the food was introduced at this 

 time, the one group being designated vegetarians, and the other, omni- 

 vorous feeders. These two groups were fed exactly the same food 

 each day, with the exception of meat and other animal foods which 

 were given about three times a week to the omnivorous feeders in addi- 

 tion to the vegetable food. The vegetable foods were as rich in protein 

 as it was possible to obtain from this class of foods, and consisted of 

 such articles as the following: fresh vegetables, such as lettuce, kale, 

 cabbage, cauliflower, clover and celery; cooked vegetables, such as 

 white, corn, brown and graham bread, biscuits, buckwheat cakes, dough- 

 nuts, crackers, cookies, oatmeal mush, fried cornmeal mush, dumplings, 

 corn, rice, baked beans, potatoes, carrots and onions; nuts, fruits and 

 grains, such as almonds, English walnuts, apples, cracked corn, wheat, 

 and corn meal. Occasionally, when the vegetarians seemed to be losing 

 ground too fast, a feed of cheese, milk, or some other animal food was 

 given. This was done only a few times soon after the vegetarians 

 were first put on their exclusive diet. 



As can be readily seen, the above articles composing the vegetarian 

 diet are either found on our tables or can readily be procurred from 

 shops. Some of them contained small portions of animal food, i.e., 

 graham muflins usually contain an egg and milk, bread often contains 

 milk, doughnuts and several other articles contain animal fat. As only 



